Hi guys , I need a bit of advice please...a few weeks ago I had a new gas filter fitted on my vailant combi. Its still under warranty thank goodness !! Now I have a leaking overflow pipe under the floorboards, not sure if it is an overflow or maybe an expansion pipe somebody said??!! Anyway the elbow joint has been glued , do i need to get special glue to fit a new joint on , and why is there a significant drip when the heating is on ? Pressure goes up to 2.2 is that too high? Thanks in advance much appreciated.